Amine and phosphatic fertilizer



NOV. 1940- w. D. BANCROFT EFAL 2,222,737

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W Patented Nov.26,1940 2,222,737

UNITED STATES PATENT OFFICE AMINE AND PHOSPHATIC FERTILIZER Wilder D. Bancroft, James K. Wilson, and John E. Rutzler, J r., Ithaca, N. Y.

Application October 21, 1938, Serial No. 236,343

Claims. (01. 71-27) Our invention relates to methods of making material such as phosphate rock in which the insoluble phosphatic materials available for plant phosphorus is of a low degree of availability, comgrowth and to new fertilizer products which acmercially important increases in yields of tomacomplish this. This application is a continuatoes, rutabagas and soy beans are obtained.

- tion-in-part of application Serial No. 113,254, Without the presence of the amine under such 5' filed November 28, 1936. circumstances, the yields were found to be con- Phosphatic materials, such as ordinary trisid'erably less. Other amines, such as dipropylcalcium phosphate, contain phosphorus which is amine, triisopropylamine, benzylamine and di-na valuable plant nutrient; but under ordinary butylamine for example, also give excellent inconditions the phosphorus in tricalcium phoscreases in yields of fruits and grains when apphate is not highly available to plants. This lack plied to soils containing unavailable phosphorus of availability of the phosphorus in ordinary or when applied to the soil in conjunction with phosphate rock, tricalcium phosphate, Thomas substantially insoluble phosphatic materials. So

slag, guano and other phosphatic materials which far as we have been able to determine, there is contain appreciable percentages of phosphorus no direct chemical reaction between our amines in only a slightly available form, has made necand the insoluble phosphatic materials which we essary the acid treatment whereby rock phosprefer to use therewith. Our invention is useful phate is converted by a strong acid, such as sulin many d diverse ypes of soils as is shown by M furic acid, to forms which are much more availthe fact that large increases in yields have been able to plants. Such processes broadly speaking obtained when amines were applied to as widely produce either the water-soluble form, such as di ferent types of soils as Dunkirk, ta monocalcium phosphate, or the slightly watersafras, Minatare and Volusia soils, for example. soluble form dicalcium phosphate, which is A variety 0f pl s ave be found o ve large somewhat available to plants and is ordinarily increases in y e When One 0 Our a es s designated as citrate soluble. applied to such soils in presence of substantially It is an object of our invention to make availi so ub e, u a ab e D O P C materials; y able the phosphorus in tricalcium phosphate or W y of e p e We ay e t e fOlIOWingl oother insoluble phosphatic materials such as matoes, White s buckwheat. barley, Y

m phosphate rock, guano, Thomas slag, calcium beans, peas, pasture grasses, and wheat. It will metaphosphate, ferric, aluminum, calcium and be seen from this enumeration that leguminous magnesium phosphates and the like, without as well as non-legumin u p a s a fruits. treating these materials by expensive processes grains, root crops and grasses all e en ou d and without subjecting them to chemical decomto respond t t pra e of u inventionposition. A new, novel and unexpected result of the ap- Further objects of our invention are to proplication of our amines to the soil, along with vide afertilizer, the phosphorus in which becomes i solu l p phati a s, r to s l 0011- available to plants after application to the soil taining unavailable phosphorus, is that it causes and which will retain its availability for a conthe phosphorus in said phosphatic materials to siderable length of time. The phosphorus in our become available to p a ts Ordinarily it Would fertilizer materials will be found in an available be expected that addition of amines to the soil form over a considerable range of depth in the would result in increased plant growth which soil compared, for example, to the phosphorus in could be accounted for wholly on the basis of phosphate rock alone. the nitrogen added in the form of the amine.

With these and other objects in View, which Quite unexpectedly, we have found that this is will be readily apparent from the ensuing denot the case. When a fertilizer such as urea is scription, our invention comprises the steps hereapplied to the soil, the increase in plant growth inaiter set forth and the products resulting from which results is due largely to the nitrogen which the steps enumerated. is thereby supplied to the growing plants. Amines We have found that when certain amines are such as we prefer to employ in the practice of applied to soil which contains residual, unavailour invention function in part to supply nitrogen able compounds of phosphorus, large increases to the growing plant. We have found, however, in plant growth result. For example, when trithat a much more important efiect of these comethylamine is applied either to a Dunkirk soil pounds is their action in and on the soil whereby which has been phosphated in past years or to unavailable phosphorus is released for use by a Dunkirk soil in conjunction with a phosphatic the growing plant in amounts far in excess, as

judged by the amount of increased growth obtained, of the amount of phosphorus that becomes available when the common nitrogen fertilizers such as calcium cyanamide, ammonium sulphate, dried proteins, sodium nitrate or urea, for example, are applied to the soil. Amines such as we employ surprisingly do not act as good nitrogen fertilizers compared to the ordinary nitrogenous fertilizers on the basis of equal amounts of nitrogen, except when there are large amounts of available phosphorus in the soil prior to the application of the amine.

In order for our amines to function well to increase the growth of plants by virtue of an action in the soil whereby the availability of unavailable phosphatic compounds and complexes is increased, we find that it often is advantageous to add phosphatic materials to the soil concurrently with the amines. This is particularly the case in soils having very small supplies of insoluble, unavailable phosphates and in soils which have never been phosphated. On the other hand, when a given soil contains from moderate to large amounts of residual, non-available phosphorus, we may prefer to apply our amines directly and without the addition of more phosphorus.

In the course of reducing our invention to practice, we have found that the particular form in which the substantially insoluble unavailable phosphatic material occurs is not of controlling importance. Thus, the amines that we prefer to use have the unsuspected property of increasing the availability of the phosphorus in a wide range of such phosphatic materials as, for example, tricalcium phosphate, rock phosphate, Thomas slag, guano, ferric phosphate, aluminum phosphate, magnesium phosphate, reverted superphosphate and other similar materials. For example, benzylamine, triethylamine, dipropylamine, tripropylamine, the corresponding isopropylamines, various normal and isobutylamines and monoamylamine, various mixtures thereof and in many cases the crude products obtained in the manufacture of said amines prior to final purification but after converting the amine salts to the corresponding free bases increase the availibility of the unavailable phosphorus in substantially insoluble phosphatic materials either when applied to the soil alone or when applied to the soil in admixture with said substantially insoluble phosphatic materials.

When our fertilizer compositions are applied to the soil, or are made in the soil as the case may be, a portion of the unavailable phosphorus in the phosphatic materials becomes solubilized so that it is more available for plant growth. While the exact mechanism of this action. is not clear to us, it appears to be a fact that a part of the solubilized phosphorus diffuses in the soil solution so that available phosphorus is to be found over a greater portion of the soil profile than would be the case in the absence of the amine.

That the increased availability of phosphorus brought about by our amines is not a transitory effect is shown by the fact that upon growing a second crop, a year later, on land treated as in the examples of the practice of our invention which are given, excellent increases in plant growth are obtained. Thus one treatment results in two years increase in plant growth of a degree that cannot be explained on the basis of either the amount of phosphorus or the amount of nitrogen added in carrying out the invention.

filed October 21, 1938, is that in the present ap- 1 plication we disclose and claim alkyl monoamines; while in co-pending application Serial No. 235,668, we disclose and. claim alkanolamines and in co-pending application Serial No. 236,342, we disclose and claim aliphatic diamines. Each of these classes is separate and distinct from the others. It is intended that the three classes of amines shall be mutually exclusive of one another. We have found that all of the amines in each of the classes have three common properties, e. g., they all peptize tricalcium phosphate in an aqueous dispersion medium free from effective amounts of coagulating metallic cations; they all increase the availability to growin plants of the phosphorus in substantially insoluble phosphatic materials; and they all function weakly compared to sodium nitrate, for example, as nitrogen fertilizers in absence of large amounts of available phosphorus.

These amines all have another characteristic property which, for some reason which is not clearly understood, marks them as useful in the practice of our invention and distinguishes them from other amines and similar compounds which do not markedly increase the availability of the phosphorus in insoluble phosphatic materials. We have found that all of these alkyl monoamines which increase the availability of phosphorus to growing plants possess the property of peptizing tricalcium phosphate, or finely ground phosphate rock, in aqueous dispersion media in which there are substantially no coagulating cations such as calcium, magnesium and iron, for example, or in aqueous dispersion media in which the concentration of monovalent cations is low. This property distinguishes our amines from compounds such as, for example, aniline, pyridine and urea which do not appreciably peptize tricalcium phosphate, or finely ground phosphate rock, in aqueous dispersion media and also do not act in the soil to markedly increase the availability to growing plants of the phosphorus present in the soil in substantially unavailable forms.

Examples of procedures which will accomplish the desired result of making the phosphorus in substantially insoluble phosphates, or phosphatic materials, available for plant growth will now be given. These examples are by way of illustration only, it being clearly understood that there are many equivalent methods which will be obvious to those skilled in the art once the details of the practice of our invention are disclosed.

Example I This is an example of compositions comprising an insoluble phosphatic material and one or more alkyl monoamines having the generic formula [CnH(2n+l)]:rNH(3:v), which when applied to the soil furnish available phosphorus to the growing plant either more efiiciently or in larger amounts than if the insoluble phosphatic material were applied alone. As a suitable amine we may employ, for example, triethylamine or dipropylamine, or tripropylamine, or triisopropylamine, or di-n-butylamine, or tri-n-butylamine, or the corresponding secondary butylamines, or a normal or secondary amylamine. Instead of using a pure amine in our compositions, we may prefer to use the crude products formed during their manufacture after converting the amine salts to the corresponding free bases. Alternatively, we may use mixtures of the pure amines and/or the crude free bases in our compositions. Owing to their volatility, we do not use in our compositions the methylamines, monoand diethylamine nor other alkyl monoamines having boiling points under 65 C. As insoluble phosphatic material we may employ, for example, tricalcium phosphate, dicalcium phosphate, iron phosphate, magnesium phosphate or aluminum phosphate. Or we may employ a mixture of these phosphates in a fairly pure form or in the form of phosphate rock of a high or inferior grade as judged by the standards of the day. Thomas slag, guano and other phosphatic materials, such as insoluble metaphosphates, may be used. The choice of insoluble phosphatic material to be used in our compositions may be varied over a very wide range, as will be apparent to those skilled in the art. While on the other hand it is of very great importance to employ the proper kind of alkyl monoamine.

It is only necessary to grind the phosphatic material to a fairly fine state of subdivision, so that it will pass through a 200-mesh sieve for instance. Clearly, many of the ordinary industrial grinding methods will serve for this purpose. The more finely divided material is, the more efiiciently will it serve to supply available phosphorus to plants and the more effective will the amine be in increasing the availability of the phosphorus therein when the composition is incorporated with the soil. From our experiments, there does not appear to be any critical particle size of the insoluble phosphatic material above which or below which the amine fails entirely to function to product a composition which when applied to the land will supply a greater than normal amount of available phosphorus for growing plants. On the other hand, the size of the particles of the insoluble phosphatic material infiuences the amount of amine that can be incorporated therewith to produce a composition having acceptable mechanical properties for easy, uniform distribution over the land. The smaller the size of the particles, the greater, within limits, is the amount of amine that can be incorporated with a given amount of a specific phosphatic material.

The amine may be incorporated with the insoluble phosphatic material in any one of several ways. For instance, the desired amount of the amine may be intimately mixed with the phosphatic material during the latter part of the dry grinding operation upon said phosphatic material provided means are employed to prevent volatilization and/or decomposition of the amine by the heat generated during said grinding. Or, the grinding may be carried out in water cooled apparatus to prevent volatilization and/or decomposition. If wet grinding is employed, the liquid used may be a water solution of the amine.

Alternatively, the phosphatic material may be mixed after being ground and while in a dry condition with the desired quantity of the desired alkyl monoamine. There are numerous wellknown methods for accomplishing this.

Again, we may prefer to mix finely ground phosphatic material with a solution of the amine. This may be done in several Ways which are familiar to those skilled in the art, using as solvent for the amine either water or organic liquids. Furthermore, the amine may be incorporated with the phosphatic material at any one of several times. For instance, they may be mixed either during or immediately after grinding, or when bagging the phosphatic material for sale, or by atomizing the amine or a solution thereof into the phosphatic material at some stage of its handling on the farm.

A number of compositions which when applied to the land will accomplish the desired result of making the phosphorus in substantially insoluble phosphatic materials more available to plants than it would be in absence of the amine will now be given. It is to be understood that these compositions are merely by way of example and that other, equivalent compositions will accomplish the desired results as well as combinations of the compositions given.

Pounds Phosphate rock 1000 Triethylamine 90 2 Phosphate rock 1000 Di-n-butylamine 100 3 Phosphate rock 1000 Triethylamine 60 4 Phosphate rock 1000 Limestone 1000 Triethylamine 175 5 Phosphate rock 1000 Triethylamine 40 Diamylamine 30 Dipropylamine 20 6 Phosphate ror-k 1000 Limestone 1000 Triethylamine 75 Diamylamine '75 Dipropylamine 30 7 Phosphate rock 1000 Di-n-butylamine 60 Di-n-amylamine 15 Tri-n-butylamine 15 8 Phosphate rock 1000 Potassium chloride 200 Sodium nitrate 400 Triethylamine 40 Di-n-amylamine 40 Dipropylamine 2O 9 Thomas slag 2000 Di-n-butylamine 130 Triisopropylamine 50 Guano 2000 Triethylamine 1'75 11 Ferric phosphate 1000 Tri-n-butylamine 20 Di-n-amylamine 60 12 Tricalcium phosphate 1000 Triethylamine v 13 Thomas sla 2000 Crude di-n-butylamine base 225 14 Phosphate rock 1000 Crude triethylamine base 15 Phosphate rock 1000 Benzylamine 85 In general, the compositions given are sufiicient in amount to treat approximately two acres of land. However, this will vary widely depending upon the fertilizer requirements of the land to which these compositions are applied.

The compositions given by way of example of the practice of our invention illustrate a few of the variations which are to be construed as covered by said invention. For instance, compositions 1, 2, 5, '7 and 15 illustrate the use of different amines; while compositions 5, 6, 7, 8, 9, and 11 illustrate the use of mixtures of amine. Various proportions of amine to insoluble phosphatic material are shown in compositions 1, 2, 3, 4, 6, and 12; while mixture number 6 shows how other fertilizer material can be incorporated with the insoluble phosphatic material and the amine so that the amount of the amine compared to the amount of phosphatic material can be increased without producing a too sticky and lumpy composition for efiicient, easy distribution over the land. Composition 8 illustrates the use of an amine and an insoluble phosphatic material in a complete fertilizer mixture. Compositions 1, 9, 10, 11, and 12 illustrate the use of a variety of phosphatic materials in our fertilizer mixtures. In the case of compositions 13 and 14, the principle of using the crude products, after they have been transformed into the free bases, of the reactions by which the amines are manufactured is illustrated.

The proportion of alkyl monoamine to insoluble phosphatic material can be varied over a wide range, although for the most effective practice of our invention we have found that the proportion should be so adjusted that when the composition is applied to the land from 10 to 190 pounds of the amine will be applied to each acre thereof. However, it should be understood that greater and lesser amounts of amine than these also will function to give larger increases in plant growth than would be obtained from the phosphatic material alone or the phosphatic material plus an amount of nitrogen equivalent to that present in the amine. Therefore, our invention is not limited to any specific range of amounts of amines.

Example II Instead of mixing an insoluble phosphatic material with an alkyl monoamine and applying the mixture to the soil, we may prefer to make the mixture in the soil. This example of the practice of our invention is shown diagrammatically in Figure 2. For this purpose a finely ground, 200 mesh, for example, phosphatic material either of high or low grade is applied to the soil at the rate of from to 2000 pounds per acre. A suitable alkyl monoamine or a combination of suitable alkyl monoamines, such as will peptize tricalcium phosphate in aqueous solution in absence of too high a concentration of metallic, coagulating cations, is then applied to the soil. In this example of the practice of our invention, we may use solutions of the low boiling amines such as, for example, the three methylamines, monoand diethylamine and/or other monoalkyl monoamines either alone or in the form of mixtures or in the form of a solution of a low boiling and a high boiling amine. In applying the amine we find that it is preferable to make a water solution thereof of a concentration of less than fifty percent and apply said solution to the land in order to ensure a uniform distribution over the land. Either higher or lower concentrations of amine can be employed in the preparation of a mixture suitable for application to the soil; the pure amine may be placed on the soil if desired. However, when the amine is applied at a time when the crop is in the soil to be treated, much less concentrated solutions than fifty percent must be employed in order to avoid a toxic effect on the plants, or else special precautions should be taken to avoid contact be tween plant and amine. In general, solutions of a strength of less than ten percent of amine are employed by preference when there is a growing crop in the ground.

For the purpose of carrying out this form of our invention, we prefer to employ not less than ten pounds of amine per acre of land and not as much as will be toxic to the plant which is to be grown on the soil. The order of application of the phosphatic material and the amine may be reversed if desired. Alternatively, we find it desirable to make a solution of a soluble fertilizer material such as potassium nitrate, by way of example, and add to such solution the proper amount of a suitable amine and apply the whole to the soil.

Example III Since many soils contain natively an abundance of substantially insoluble and unavailable phosphatic materials, we prefer in many such cases to apply one or more of our alkyl monoamines or a mixture thereof to the soil in the manner and at the rate indicated in Example II, without first or subsequently applying any phosphatic material whatever. Figure 3 is a diagrammatic representation of this example of our invention. Also, many soils contain quite large supplies of substantially insoluble phosphatic materials resulting from the reversion and fixation of phosphorus fertilizers which have been applied thereto previously. Such soils as these benefit markedly from the application of our amines or mixtures thereof without further application of phosphorous.

On such soils as these we prefer to apply from ten to five hundred pounds per acre of our alkyl monoamines.

We have found in soils such as these that it is only necessary to incorporate the amine with the soil in any of the ways indicated in Example II to achieve the results of increased phosphorus availability and increased plant growth. In this example of the practice of our invention we may use solutions of the low boiling amines such as, for example, the three methyl-amines, monoand diethylamine and/or other monoalkyl monoamines either alone or in the form of mixtures or in the form of a solution of a low boiling and z,zzz,1 or

high boiling amine. Alternatively to broadcasting the amine or an aqueous solution thereof over the land, we may prefer to apply the amine or its solution in rows beside the planted seeds or growing plants as the case may be. When this procedure is adopted, we have found that a smaller total quantity of our amines is required to produce the maximum amount of increased growth.

It will be seen readily by those skilled in the art that this example of the practice of our invention is merely a variant of Example I in that in the present example the mixture of phosphatic material and amine is formed in the soil rather than being preformed and then added to the soil as in Example I.

While we have described the preferred embodiment of our invention, we wish it to be understood that we do not confine ourselves to the precise details herein set forth by way of illustration, as it is apparent that many changes and variations may be made therein, by those skilled in the art, without departing from the spirit of the invention or exceeding the scope of the appended claims.

We claim:

1. A new fertilizer composition comprising a finely divided and substantially insoluble phosphate material and an amine having a boiling point of more than C. and a formula corresponding to the generic formula the weight of said amine amounting to approximately six to nine percent by weight of the phosphatic material used in the said composition.

2. A new fertilizer composition comprising a finely divided and substantially insoluble phosphatic material and an alkyl monoamine, the Weight of said amine amounting to approximately six to nine percent of the phosphatic material present in the said composition.

3. A new fertilizer composition comprising a finely divided and substantially insoluble phosphatic material and triethylamine, said amine constituting approximately six to nine percent by weight of the phosphatic material present in the said composition.

4. A new fertilizer composition comprising a finely divided and substantially insoluble phosphatic material and di-n-butylamine, said amine being present in peptizing proportions.

5. A new fertilizer composition comprising a finely ground and substantially insoluble phosphatic material and dipropylamine, said amine constituting approximately nine percent by weight of the phosphatic material present in the said composition.

WILDER D. BANCROF'I. JAMES K. WILSON. JOHN E. RUTZLER, JR. 

